The present invention relates to the field of building design; more specifically, it relates to emergency stairwells for multistory building.
Most multistory buildings are provided with emergency stairwells to provide quick evacuation of the building in the event of an emergency such as a fire and as alternative evacuation routes to elevators.
In conventional emergency stairwell design, the widths of the stairwell remains constant from the uppermost floors serviced by the emergency stairwell to the lowermost floors serviced by the emergency stairwell. This design is predicated on the assumption that persons entering the emergency stairwell from lower floors will have reached the lowermost egress from the emergency stairwell before persons entering the emergency stairwell from upper floors reach the lower floors.
One problem with this assumption is that in high buildings, people get tired and their rate of descent slows down. As persons from upper floors overtake these now, slower moving persons, congestion builds up slowing egress still more. A similar slowdown can occur when more vigorous or able persons overtake less vigorous or able persons.
Another problem with conventional emergency stairwells, especially in very high buildings is, other than floor numbering, there is no stimulus that indicates the progress is being made to an eventual egress. Going down floor after floor can become claustrophobic and induce panic in the evacuees.
Providing more emergency stairwells does not address these problems, and building uniformly wider emergency staircases, while addressing some of the problems is wasteful of expensive floor space.
Therefore there is a need for an improved emergency stairwell that reduces or eliminates buildup of congestion on sections of the stairwell servicing lower floors, provides some more than a textual indication that progress toward an egress is being made and does not consume unacceptable amounts of floor space.
A first aspect of the present invention is an emergency stairwell for a building having multiple floors comprising: at least one landing associated with each the floor, each landing increasing in width in at least one horizontal direction from an uppermost landing of an upper floor to a lowermost landing of a lower floor; and at least one set of stairs extending between adjacent pairs of landings.
A second aspect of the present invention is an emergency stairwell for a building having multiple floors comprising: a plurality of stairwell sections, each section comprising: a set of landings, one landing of each set of landings associated with one the floor, and at least one set of stairs extending between adjacent pairs of landings, all landings within a stairwell section having the same width in at least one horizontal direction; and each stairwell section and associated landings within that stairwell section increasing in width in at least one horizontal direction from an uppermost stairwell section associated with a group of adjacent upper floors to a lowermost stairwell section associated with a group of adjacent lower floors.